Non-Invasive Biomarker of Antibody-Mediated Allograft Rejection

Abstract

Disclosed herein are methods for the early, non-invasive diagnosis of antibody-mediated allograft rejection, methods of identifying a population of allograft recipients at risk for developing antibody-mediated rejection and methods of monitoring the treatment of patients for antibody-mediated rejection.

1 . A method of detecting antibody-mediated rejection in an allograft transplant recipient, the method comprising:
 determining the concentration of C4d+/CD144+ endothelial microparticles (EMP) in a blood sample obtained from the allograft transplant recipient after transplant;   wherein if (i) the concentration of C4d+/Cd144+ EMP in the blood sample is greater than about seven standard deviations above the mean of a reference C4d+/CD144+ EMP concentration from a healthy individual, the allograft transplant recipient has antibody-mediated rejection and treatment for antibody-mediated rejection should be initiated, or (ii) the concentration of C4d+/Cd144+ EMP in the blood sample is less than about seven standard deviations above the mean of a reference C4d+/CD144+ EMP concentration from a healthy individual, the allograft transplant recipient does not have antibody-mediated rejection.   
     
     
         2 . The method according to  claim 1 , wherein the blood sample is serum, plasma, or platelet poor plasma. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . The method according to  claim 4 , wherein the blood sample contains normal serum creatinine levels. 
     
     
         6 . The method according to  claim 4 , wherein the blood sample contains increased serum creatinine levels. 
     
     
         7 . The method according to  claim 1 , wherein the method further comprises determining donor-specific antibodies in the blood sample from the allograft transplant recipient. 
     
     
         8 . The method according to  claim 1 , wherein the method further comprises obtaining an allograft biopsy. 
     
     
         9 . (canceled) 
     
     
         10 . The method according to  claim 1 , wherein if the concentration of CD4+/CD144+ EMP in the blood sample is greater than about eight standard deviations above the mean of the reference C4d+/CD144+ EMP concentration, the allograft transplant recipient has antibody-mediated rejection and treatment for antibody-mediated rejection should be initiated. 
     
     
         11 . The method according to  claim 1 , wherein if concentration of CD4+/CD144+ EMP in the blood sample is less than about eight standard deviations above the mean of the reference C4d+/CD144+ EMP concentration, the allograft transplant recipient does not have antibody-mediated rejection. 
     
     
         12 . The method according to  claim 1 , wherein if the allograft transplant recipient has initiated therapy for transplant rejection, the method further comprises
 determining the concentration of C4d+/CD144+ EMP in a blood sample obtained from the allograft transplant recipient after the initiation of treatment for AMR;   wherein if (i) the concentration of C4d+/Cd144+ EMP in the blood sample is greater than about seven standard deviations above the mean of a reference C4d+/CD144+ EMP concentration from a healthy individual, the antibody-mediated rejection treatment is not effective and an alternative treatment should be initiated, or (ii) the concentration of C4d+/Cd144+ EMP in the blood sample is less than about seven standard deviations above the mean of a reference C4d+/CD144+ EMP concentration from a healthy individual, the antibody-mediated rejection treatment is effective and either should be maintained or discontinued.   
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . A method of maintaining allograft function in an allograft recipient comprising:
 determining the concentration of C4d+/CD144+ EMP in a blood sample from the allograft transplant recipient after transplant and before onset of transplant rejection symptoms;   wherein if (i) the concentration of C4d+/Cd144+ EMP in the blood sample is greater than about seven standard deviations above the mean of a reference C4d+/CD144+ EMP concentration from a healthy individual, the allograft recipient has antibody-mediated rejection (AMR) and AMR treatment is provided to the allograft recipient; or (ii) the concentration of C4d+/Cd144+ EMP in the blood sample is less that about seven standard deviations above the mean of a reference C4d+/CD144+ EMP concentration from a healthy individual, the allograft transplant recipient does not have AMR and no treatment is necessary.   
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . (canceled) 
     
     
         25 . The method according to  claim 21 , wherein the method further comprises determining donor-specific antibodies in the blood sample from the allograft transplant recipient. 
     
     
         26 . The method according to  claim 21 , wherein the method further comprises obtaining an allograft biopsy. 
     
     
         27 . (canceled) 
     
     
         28 . The method according to  claim 21 , wherein if the concentration of CD4+/CD144+ EMP in the blood sample is greater than about eight standard deviations above the mean of the reference C4d+/CD144+ EMP concentration, the allograft recipient has antibody-mediated rejection treatment and AMR treatment is provided to the allograft recipient. 
     
     
         29 . The method according to  claim 21 , wherein if the concentration of CD4+/CD144+ EMP in the blood sample is less than about eight standard deviations above the mean of the reference C4d+/CD144+ EMP concentration, the allograft transplant recipient does not have AMR and no treatment is necessary. 
     
     
         30 . A method of identifying an transplant recipient at risk of allograft rejection, wherein the transplant recipient is identified by:
 determining the concentration of C4d+/CD144+ EMP in a blood sample obtained from the transplant recipient after transplant and before onset of transplant rejection symptoms;   wherein, the transplant recipient is at risk of allograft rejection if the concentration of C4d+/CD144+ EMP in the blood sample is greater than about seven standard deviations above the mean of a reference C4d+/CD144+ EMP concentration from a healthy individual.   
     
     
         31 . (canceled) 
     
     
         32 . (canceled) 
     
     
         33 . (canceled) 
     
     
         34 . The method according to  claim 30 , wherein the subject exhibits normal serum creatinine levels at the time of sampling. 
     
     
         35 . The method according to  claim 30 , wherein the subject exhibits increased serum creatinine levels at the time of sampling. 
     
     
         36 . The method according to  claim 30 , wherein the method further comprises determining donor-specific antibodies in the blood sample from the allograft transplant recipient. 
     
     
         37 . The method according to  claim 30 , wherein the method further comprises obtaining an allograft biopsy. 
     
     
         38 . (canceled) 
     
     
         39 . The method according to  claim 30 , wherein if the concentration of CD4+/CD144+ EMP in the blood sample is greater than about eight standard deviations above the mean of the reference C4d+/CD144+ EMP concentration, the allograft transplant recipient is at risk of allograft rejection.